US 11,043,109 B2Granted

Fire notification facility

AssigneeHochiki Corporation

InventorsYoshihiro Matsuda, Shigeru Kaneko, Takehiro Ono, Akira Ishida

Life of this patent

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Abstract

A fire detector is connected to a loop transmission path connected to a receiver. When the loop transmission path is normal, a communication connection is made from a transmitting unit to the fire detector to monitor fire. When a break fault occurs in the loop transmission path, a break monitoring control unit turns switching circuit units ON to connect a termination of the loop transmission path to the transmitting unit. To the loop transmission path, a relay detects a current normal direction at normal and a current reverse direction at the time of occurrence of a break for transmission to the receiver. When a break occurs in the loop transmission path, a break section determining unit of the receiver determines, as a break section, a section in which the current normal direction detected by a plurality of the relays is changed to the current reverse direction.

Claims11

Dependent claims

A fire notification facility comprising:

a receiver or a relay connected to the receiver;
a loop transmission path connected in a loop shape to the receiver or the relay;
a plurality of fire detectors provided to the loop transmission path;
a break monitoring control unit connected to a terminating end of the loop transmission path, a transmitting unit of the receiver or the relay being connected to a starting end of the loop transmission path and configured to transmit a signal to at least one of the plurality of fire detectors to monitor fire when the loop transmission path is normal, and the break monitoring control unit being configured to connect the terminating end of the loop transmission path to the transmitting unit by a switching unit for transmission of a signal from both the terminating end of the loop transmission path and the starting end of the loop transmission path to at least one of the plurality of fire detectors to monitor fire when a break occurs in the loop transmission path;
a plurality of current direction detecting units connected to the loop transmission path, each of the plurality of current direction detecting units having a unique address set thereto, and being configured to detect a current direction flowing through the loop transmission path in a predetermined direction as a current normal direction and detect a current direction flowing opposite to the current normal direction as a current reverse direction;
and
a break section determining unit provided to the receiver or the relay, the break section determining unit being configured to:
(i) determine, as a break section, a section in which the current normal direction detected at the plurality of current direction detecting units has changed to the current reverse direction when a break occurs in the loop transmission path;
and (ii) notify of the break section.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 16/795,993Filed 20 Feb 2020 · continuation
Priority: JP JP2018-00788922 Jan 2018
Published: US 2020/0184801 A111 Jun 2020
Granted: 22 Jun 2021
Term ends: Not estimatedThe source records don’t support an estimate.

Classification7 codes

G08B 25/04
Characterised by the transmission medium: using a single signalling line, e.g. in a closed loop
G08B 17/10
Fire alarms; Alarms responsive to explosion: actuation by presence of smoke or gases , e.g. automatic alarm devices for analysing flowing fluid…
G08B 25/045
Using a single signalling line, e.g. in a closed loop: with sensing devices and central station in a closed loop, e.g. McCullough loop
G08B 26/004
Alarm systems in which substations are interrogated in succession by a central station: with common interrogation of substations